Activity approach in design of specialized visualization systems

The article discusses the application of activity approach in designing specialized interfaces and visualization systems. Activity approach is a psychological theory developed by the Russian academics of the XX century which suggests analyzing professional work as a type of activity. Activity presupposes consciousness, purposefulness and setting tasks, the accomplishment of which is aimed at achieving a goal. Activity can be broken down into actions serving to accomplish the tasks, and actions, in turn, are broken down into operations. The same activity can be carried out through different operations, and the same operations can be combined into different types of activity. Activity approach in interface design is applied to mass and professional instrumental interfaces. The article provides examples of activity analysis in terms of the used instrumental interfaces; it describes approaches to designing real interfaces for medical purposes, considers the design tasks for specialized visualization systems. For this purpose, the phenomenon of insight can be used as one of the criteria of visualization quality. The article also points out the issues of using virtual reality in scientific visualization. It provides the results of the experiment analyzing the influence of the presence phenomenon in virtual reality on the solution of intellectual tasks, and the basics of visualization system user activity. The article discusses the analysis of specialized (both professional and mass) interfaces serving as instruments in purposeful and productive activity. The analysis is carried out from the perspective of the activity theory and several topics in the fields of psychology and physiology. It is generally believed that the history of interface design clarifies some subtle aspects of modern interactive systems. Further, examples of prototype implementations of service interfaces are provided. Future possibilities for introducing the activity approach into the practical design of specialized interactive systems are also under review. © 2017 Lavoisier. All rights reserved

Collective Interatomic Decay of Multiple Vacancies in Clusters

We predict that inner-shell ionization of more than one atom (or molecule) in a cluster, e.g., by intense free-electron laser radiation, can lead to an interatomic decay process in which the formed vacancy states decay simultaneously, while a neighboring neutral species is ionized. This collective decay phenomenon can be regarded as a transfer of two or more virtual photons from the ionized cluster units to a neutral one. Simulations of collective decay in (4s−1, 4s−1) (Kr+)2Ar show that the two-virtual-photon process can be competitive with the dissociative nuclear dynamics of the doubly ionized cluster. Generality of the collective interatomic decay is discussed

Non-classical properties of quantum wave packets propagating in a Kerr-like medium

We investigate non-classical effects such as fractional revivals, squeezing and higher-order squeezing of photon-added coherent states propagating through a Kerr-like medium.The Wigner functions corresponding to these states at the instants of fractional revivals are obtained, and the extent of non-classicality quantified.Comment: 8 pages, 10 figure

A subjective study of the presence experience phenomenon

Background. Presence phenomenon is aт important component of human interaction using virtual reality. Virtual reality is used actively in such spheres as Education, Research, Psychotherapy, Surgery, Entertainment and Games. The hidden part of the presence experience phenomenon deserves great interest. The researcher has to answer the following questions when conducting a research: 1. what exactly does the person experiencing the presence feel? 2. how much does a person «forget» about what is happening around them in the real world? 3. is it possible to simultaneously feel one’s presence in both worlds – real, where a person is physically present, and virtual, where a person is immersed by specific hardware and software that generate virtual reality? The Objective of the paper is to provide a description of the subjective presence experience, to show features of presence experience types. Design. The paper includes the review of modern research on the presence phenonmenon. The course of the study is described: conditions for experiencing the phenomenon of presence (e.g. virtual flight over the city) were designed to coincide with theoretical factors that enhance or weaken the experience of the phenomenon of presence. Following the first stage, the subjects were interviewed using structured interviews in order to systematize their subjective experience. The paper provides a qualitative analysis of the test subjects’ answers. The study involved 18 people, 5 males and 13 females aged 18 to 28 years. Results. The influence of factors contributing to the emergence of presence is reflected in the subjective experience, types of experiencing different types of presence (e.g. environmental, social, personal) were highlighted. The contradictory notions about the position of one’s body, the location of other people and other components of the phenomenon of presence are shown. Conclusion. The phenomenon of presence is a complex experience within which the perception of time, space, body, physical laws is distorted

Evolution of human computer interaction

The work is devoted to the review of the development the human-computer interaction. In the first sections the history of computing in the "pre-computer" era is briefly described and then the early history of modern computing, methods of the first computers controlling and the tasks of programmers at this stage are described. It describes the methods of interaction with the first -generation computers using the remote control elements, punched cards and punched tapes. The section, devoted to the second generation computers, describes the emergence of high-level operating systems and programming languages. At this point, there are such means of interaction with the computer as the displays and, respectively, such programming tools as interactive languages and interactive debuggers. Research is also beginning on principles of human-computer interaction the infancy of the discipline "computer graphics", the development of computer graphics packages and the emergence of interactive computer graphics standards are considered. In the section “Revolutions in computer science” describes the appearance of a large number of the same series computers and the first super-computers in the context of human-computer interaction. Revolutionary changes are considered in computer graphics and emerging of the science discipline “computer visualization” with its parts “scientific visualization”, “software visualization”, “information visualization” and also “programming by demonstration”. The information about the attempt to create a fifth generation computer based on logical programming is given. It is told about the initial period of teaching programming. The creation of computer networks and the emergence of personal computing as well as the creation the tools of modern parallel computing have become the important stages in the development of modern computing. The virtual reality becomes an important computer visualization tool. The modern state of human-computer interfaces is characterized primarily by emerging of natural interfaces which can be attributed Brain-Computer Interface (Neurocomputer interface, Brain-Computer Interfaces), interfaces based on the direct use of nerve impulses, speech recognition, recognition of lip movement, mimic recognition and eye tracking (Eye Gaze or Eye Tracking), haptic interfaces and also interfaces giving tactile feedback (allowing you to feel the touch),motion capture interfaces the entire human body or individual organs (head, entire arm, hands, fingers, legs), motion capture toolkits,in particular, interfaces based on leg movements (foot-operated computer interfaces), sign interfaces, sign languages. We briefly describe the activity approach to the design of interfaces and also some problems concerning the problem of mass interfaces. Finally, we discuss a number of problems arising from the increasing capabilities of modern computers. The work is in the nature of a popular science article and it largely reflects the subjective impressions of the author. © 2020 National Research Nuclear University. All rights reserved

Time dependent partial waves and vortex rings in the dynamics of wave packets

We have found a new class of time dependent partial waves which are solutions of time dependent Schr\"odinger equation for three dimensional harmonic oscillator. We also showed the decomposition of coherent states of harmonic oscillator into these partial waves. This decomposition appears perticularly convenient for a description of the dynamics of a wave packet representing a particle with spin when the spin--orbit interaction is present in the hamiltonian. An example of an evolution of a localized wave packet into a torus and backwards, for a particular initial conditions is analysed in analytical terms and shown with a computer graphics.Comment: 10 pages, LaTeX, 6 postscript figures, submitted to J. Phys. A: Math. Ge

Surprises in the suddenly-expanded infinite well

I study the time-evolution of a particle prepared in the ground state of an infinite well after the latter is suddenly expanded. It turns out that the probability density $|\Psi(x, t)|^{2}$ shows up quite a surprising behaviour: for definite times, {\it plateaux} appear for which $|\Psi(x, t)|^{2}$ is constant on finite intervals for $x$. Elements of theoretical explanation are given by analyzing the singular component of the second derivative $\partial_{xx}\Psi(x, t)$. Analytical closed expressions are obtained for some specific times, which easily allow to show that, at these times, the density organizes itself into regular patterns provided the size of the box in large enough; more, above some critical time-dependent size, the density patterns are independent of the expansion parameter. It is seen how the density at these times simply results from a construction game with definite rules acting on the pieces of the initial density.Comment: 24 pages, 14 figure